1. Field of the Invention
The present invention relates to cellulosic fibrous webs having improved wet and dry strength properties, said webs having been treated with cationic polygalactomannan compositions and an amic acid copolymer.
2. Description of the Prior Art
U.S. Pat. No. 4,391,878 teaches that water soluble copolymers containing the half acid, half amide structure of amic acids can be used to increase the wet strength of paper. Said patent discloses at Column 3 lines 19-33 a means for imparting cationic character to the copolymer which makes it attractive to anionic cellulose fibers for deposition in the wet end of a paper machine.
It is known in the paper making art that negatively charged (anionic) materials can be attached to the negatively charged cellulosic fibers of paper through the use of positively charged (cationic) materials which attach themselves to the negatively charged cellulosic fibers by electrical attraction and either simultaneously or subsequently attach or attract the anionic material on the cellulosic fibrous structure. See, for example, U.S. Pat. No. 3,067,088 granted Dec. 4, 1962 to Hofreiter et al. It is the object of the present invention to provide a material for fixing the wet strength resins of U.S. Pat. No. 4,391,878 to cellulosic fibers, thereby avoiding the necessity of modifying such resins so as to impart to them a cationic character.